gdb/mips64-obsd-tdep.c

   1 /* Target-dependent code for OpenBSD/mips64.
   2
   3    Copyright (C) 2004-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbtypes.h"
  22 #include "osabi.h"
  23 #include "regcache.h"
  24 #include "regset.h"
  25 #include "trad-frame.h"
  26 #include "tramp-frame.h"
  27
  28 #include "obsd-tdep.h"
  29 #include "mips-tdep.h"
  30 #include "solib-svr4.h"
  31
  32 /* The MIPS64 Floating-Point Quad-Precision format is similar to
  33    big-endian IA-64 Quad-Precision format.  */
  34 #define floatformats_mips64_quad floatformats_ia64_quad
  35
  36 #define MIPS64OBSD_NUM_REGS 73
  37
  38 /* Core file support.  */
  39
  40 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  41    in the general-purpose register set REGSET to register cache
  42    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  43
  44 static void
  45 mips64obsd_supply_gregset (const struct regset *regset,
  46                            struct regcache *regcache, int regnum,
  47                            const void *gregs, size_t len)
  48 {
  49   const char *regs = (const char *) gregs;
  50   int i;
  51
  52   for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
  53     {
  54       if (regnum == i || regnum == -1)
  55         regcache->raw_supply (i, regs + i * 8);
  56     }
  57 }
  58
  59 /* OpenBSD/mips64 register set.  */
  60
  61 static const struct regset mips64obsd_gregset =
  62 {
  63   NULL,
  64   mips64obsd_supply_gregset
  65 };
  66
  67 /* Iterate over core file register note sections.  */
  68
  69 static void
  70 mips64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
  71                                          iterate_over_regset_sections_cb *cb,
  72                                          void *cb_data,
  73                                          const struct regcache *regcache)
  74 {
  75   cb (".reg", MIPS64OBSD_NUM_REGS * 8, MIPS64OBSD_NUM_REGS * 8,
  76       &mips64obsd_gregset, NULL, cb_data);
  77 }
  78 \f
  79
  80 /* Signal trampolines.  */
  81
  82 static void
  83 mips64obsd_sigframe_init (const struct tramp_frame *self,
  84                           struct frame_info *this_frame,
  85                           struct trad_frame_cache *cache,
  86                           CORE_ADDR func)
  87 {
  88   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  89   CORE_ADDR sp, sigcontext_addr, addr;
  90   int regnum;
  91
  92   /* We find the appropriate instance of `struct sigcontext' at a
  93      fixed offset in the signal frame.  */
  94   sp = get_frame_register_signed (this_frame,
  95                                   MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
  96   sigcontext_addr = sp + 32;
  97
  98   /* PC.  */
  99   regnum = mips_regnum (gdbarch)->pc;
 100   trad_frame_set_reg_addr (cache,
 101                            regnum + gdbarch_num_regs (gdbarch),
 102                             sigcontext_addr + 16);
 103
 104   /* GPRs.  */
 105   for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
 106        regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
 107     trad_frame_set_reg_addr (cache,
 108                              regnum + gdbarch_num_regs (gdbarch),
 109                              addr);
 110
 111   /* HI and LO.  */
 112   regnum = mips_regnum (gdbarch)->lo;
 113   trad_frame_set_reg_addr (cache,
 114                            regnum + gdbarch_num_regs (gdbarch),
 115                            sigcontext_addr + 280);
 116   regnum = mips_regnum (gdbarch)->hi;
 117   trad_frame_set_reg_addr (cache,
 118                            regnum + gdbarch_num_regs (gdbarch),
 119                            sigcontext_addr + 288);
 120
 121   /* TODO: Handle the floating-point registers.  */
 122
 123   trad_frame_set_id (cache, frame_id_build (sp, func));
 124 }
 125
 126 static const struct tramp_frame mips64obsd_sigframe =
 127 {
 128   SIGTRAMP_FRAME,
 129   MIPS_INSN32_SIZE,
 130   {
 131     { 0x67a40020, ULONGEST_MAX },               /* daddiu  a0,sp,32 */
 132     { 0x24020067, ULONGEST_MAX },               /* li      v0,103 */
 133     { 0x0000000c, ULONGEST_MAX },               /* syscall */
 134     { 0x0000000d, ULONGEST_MAX },               /* break */
 135     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
 136   },
 137   mips64obsd_sigframe_init
 138 };
 139
 140 \f
 141 static void
 142 mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 143 {
 144   /* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
 145      way GDB works, forces us to pretend we can handle them all.  */
 146
 147   set_gdbarch_iterate_over_regset_sections
 148     (gdbarch, mips64obsd_iterate_over_regset_sections);
 149
 150   tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
 151
 152   set_gdbarch_long_double_bit (gdbarch, 128);
 153   set_gdbarch_long_double_format (gdbarch, floatformats_mips64_quad);
 154
 155   obsd_init_abi(info, gdbarch);
 156
 157   /* OpenBSD/mips64 has SVR4-style shared libraries.  */
 158   set_solib_svr4_fetch_link_map_offsets
 159     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 160 }
 161
 162 void
 163 _initialize_mips64obsd_tdep (void)
 164 {
 165   gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD,
 166                           mips64obsd_init_abi);
 167 }